Personally, I've been reading a lot, checking out succulent sale sites (Succulent Marketplace for example has people who are pretty accurate on IDs for the plants sold), and trying to get a feel for which species have which characteristics.
A lot of the Echeverias still look all alike to me, but haworthias/aloes are becoming more familiar.
I hope to eventually get a book like this, but more because I like this kind of book than because it would be exhaustive: https://www.amazon.com/Complete-Illustrated-Guide-Growing-Succulents/dp/1780190921